Locking gas spring for hospital beds, coach seat back , wheel chair and massage chairs etc. both spring locking and rigid locking are available Pls contact with us if you are interested. RodDia (mm) CylinderDia (mm) Stroke (mm) L.Max (mm) Force (n) 10 22 <=150 180-400 150-800 10 27 <=260 180-800 150-900